Above-room-temperature chiral skyrmion lattice and Dzyaloshinskii–Moriya interaction in a van der Waals ferromagnet Fe3−xGaTe2
Chenhui Zhang, Ze Jiang, Jiawei Jiang, Wa He, Junwei Zhang, Fanrui Hu, Shishun Zhao, Dongsheng Yang, Yakun Liu, Yong Peng, Hongxin Yang, Hyunsoo Yang
Abstract
Abstract Skyrmions in existing 2D van der Waals (vdW) materials have primarily been limited to cryogenic temperatures, and the underlying physical mechanism of the Dzyaloshinskii–Moriya interaction (DMI), a crucial ingredient for stabilizing chiral skyrmions, remains inadequately explored. Here, we report the observation of Néel-type skyrmions in a vdW ferromagnet Fe 3− x GaTe 2 above room temperature. Contrary to previous assumptions of centrosymmetry in Fe 3− x GaTe 2 , the atomic-resolution scanning transmission electron microscopy reveals that the off-centered Fe ΙΙ atoms break the spatial inversion symmetry, rendering it a polar metal. First-principles calculations further elucidate that the DMI primarily stems from the Te sublayers through the Fert–Lévy mechanism. Remarkably, the chiral skyrmion lattice in Fe 3− x GaTe 2 can persist up to 330 K at zero magnetic field, demonstrating superior thermal stability compared to other known skyrmion vdW magnets. This work provides valuable insights into skyrmionics and presents promising prospects for 2D material-based skyrmion devices operating beyond room temperature.